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State of the Code

Currently working on updating the software to match BOLT13 rev1.

If you have any questions or comments regarding the project or watchtowers in general, feel free to reach out on Slack.

The Eye of Satoshi (TEOS)

The Eye of Satoshi is a Lightning watchtower compliant with BOLT13, written in Python 3.

python-teos consists in four main modules:

  • teos: including the tower's main functionality (server-side).
  • cli: including a reference command line interface.
  • common: including shared functionality between server and client side (useful to build a client).
  • watchtower-plugin: including a watchtower client plugin for c-lightning.

Additionally contrib contains tools that are external to the tower (currently teos_client, an example Python client for the tower).

Tests for every module can be found at tests.


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Running TEOS

Make sure bitcoind is running before running TEOS (it will fail at startup if it cannot connect to bitcoind). You can find here a sample config file.

Starting the TEOS daemon 👁

Once installed, you can start the tower by running:


Configuration file and command line parameters

teos comes with a default configuration that can be found at teos/

The configuration includes, amongst others, where your data folder is placed, what network it connects to, etc.

To change the configuration defaults you can:

  • Define a configuration file named teos.conf following the template (check teos/template.conf) and place it in the data_dir (that defaults to ~/.teos/)

and / or

  • Add some global options when running the daemon (run teosd -h for more info).

Passing command line options to teosd

Some configuration options can also be passed as options when running teosd. We can, for instance, pick the network as follows:

teosd --btcnetwork=regtest

Running TEOS in another network

By default, teos runs on mainnet. In order to run it on another network you need to change the network parameter in the configuration file or pass the network parameter as a command line option. Notice that if teos does not find a bitcoind node running in the same network that it is set to run, it will refuse to run.

The configuration file option to change the network where teos will run is btc_network under the bitcoind section:

btc_rpc_user = user
btc_rpc_password = passwd
btc_rpc_connect = localhost
btc_network = mainnet

For regtest, it should look like:

btc_rpc_user = user
btc_rpc_password = passwd
btc_rpc_connect = localhost
btc_network = regtest

Running teos in a docker container

A teos image can be built from the Dockerfile located in docker. You can create the image by running:

cd python-teos
docker build -f docker/Dockerfile -t teos .

Then you can create a container by running:

docker run -it -e ENVS teos

Notice that ENV variables are optional, if unset the corresponding default setting is used. The following ENVs are available:

- API_BIND=<teos_api_hostname>
- API_PORT=<teos_api_port>
- RPC_BIND=<teos_rpc_hostname>
- RPC_PORT=<teos_rpc_port>
- BTC_NETWORK=<btc_network>
- BTC_RPC_CONNECT=<btc_node_hostname>
- BTC_RPC_PORT=<btc_node_port>
- BTC_RPC_USER=<btc_rpc_username>
- BTC_RPC_PASSWORD=<btc_rpc_password>
- BTC_FEED_CONNECT=<btc_zmq_hostname>
- BTC_FEED_PORT=<btc_zmq_port>

You may also want to run docker with a volume, so you can have data persistence in teos databases and keys. If so, run:

docker volume create teos-data

And add the the mount parameter to docker run:

--mount source=teos-data,target=/root/.teos

If you are running teos and bitcoind in the same machine, continue reading for how to create the container based on your OS.

bitcoind running on the same machine (UNIX)

The easiest way to run both together in he same machine using UNIX is to set the container to use the host network.

For example, if both teos and bitcoind are running on default settings, run

docker run --network=host \
  --name teos \
  --mount source=teos-data,target=/root/.teos \
  -e BTC_RPC_USER=<rpc username> \
  -e BTC_RPC_PASSWD=<rpc password> \
  -it teos

Notice that you may still need to set your RPC authentication details, since, hopefully, your credentials won't match the teos defaults.

bitcoind running on the same machine (OSX or Windows)

Docker for OSX and Windows does not allow to use the host network (nor to use the docker0 bridge interface). To workaround this you can use the special host.docker.internal domain.

docker run -p 9814:9814 \
  --name teos \
  --mount source=teos-data,target=/root/.teos \
  -e BTC_RPC_CONNECT=host.docker.internal \
  -e BTC_FEED_CONNECT=host.docker.internal \
  -e BTC_RPC_USER=<rpc username> \
  -e BTC_RPC_PASSWD=<rpc password> \
  -e API_BIND= \
  -it teos

Notice that we also needed to add API_BIND= to bind the API to all interfaces of the container. Otherwise it will bind to localost and we won't be able to send requests to the tower from the host.

Tower id and signing key

teos needs a pair of keys that will serve as tower id and signing key. The former can be used by users to identify the tower, whereas the latter is used by the tower to sign responses. These keys are automatically generated on the first run, and can be refreshed by running teos with the --overwritekey flag.

Interacting with a TEOS Instance

You can interact with a teos instance (either run by yourself or someone else) by using teos-cli under teos/cli. This is an admin tool that has privileged access to the watchtower, and it should therefore only be used within a trusted environment (for example, the same machine).

While teos-cli works independently of teos, it shares the same configuration file by default, of which it only uses a subset of its settings. The folder can be changed using the --datadir command line argument, if desired.

For help on the available arguments and commands, you can run:

teos-cli -h

Interacting with TEOS as a client

The contrib/client folder contains an example Python client that can interact with the watchtower in order to register, add appointments and later retrieve them.

See here for more information on how to use the client.

Note that while the client is a simple way to interact with teos, ideally its functionality should be part of your wallet or lightning node. teos_client can be used as an example for how to send data to a BOLT13 compliant watchtower.


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